The present invention relates to a storage system and management method thereof, and, for instance, is suitably employed in a storage system which virtualizes a volume of a certain disk array device with another disk array device.
Conventionally, a storage system which directly connects a disk array device to a host system and stores data in such disk array device was widely prevalent. Thus, in order for the host system to access data of a disk array device connected to another host system, the host system had to be connected, via such other host system, to the disk array device connected to the other host system.
Whereas, pursuant to the advancement of network technology in recent years and the exponential increase in the data volume to be handled by storage systems, the host system for inputting and outputting data and the storage system for storing data are being decentralized, and a storage system has been developed where a plurality of host systems are connected to disk array devices via a network, and the respective host systems share the data of the respective disk array devices.
As an example of such a storage system, there are, for example, a SAN (Storage Area Network) storage system that connects a host system and a disk array device via a SAN and provides block access service to the host system, and a NAS (Network Attached Storage) storage system that connects a host system and a disk array device via an IP network or the like and provides file access service to the host system.
Further, in recent years, proposed is a storage system having a first disk array device connected to a host system and a second disk array device connected to this first disk array device, wherein a plurality of disk array devices are integrated by mapping a logical volume of a second disk array device to a virtual volume of the first disk array device, and the first disk array device provides the logical volume of the second disk array device to the host system as though it is its own logical volume (e.g. refer to Japanese Patent Laid-Open Publication No. 2005-107645).